Permanent waving solutions and method



United States Patent PERMANENT WAVING SOLUTIONS AND METHOD Everett G. McDonough, Yonkers, N. Y., assignor, by mesne assignments, to Tide Water Patent Development Company, Incorporated, Norfolk, Va., a corporation of Virginia I No Drawing. Application August 13, 1949, Serial No. 110,239

Claims. (Ci. 132-7) This invention relates generally to the-art of permanently altering the physical form-or shape of hair, and, more particularly, to the artof permanently waving hair. This application is a continuation-in-part of my cope'nding application Serial No. 398,235, filed June 16, 1941 now Pat. No. 2,577,710.

It is known that the physical form or shape of hair can be permanently altered without injury to the hair structure by utilizing three forces, namely, a mechanical force, a chemical or softening force, and a fixing or setting force. More particularly, in permanent waving the mechanical force is set up by winding the hair in curls as on mandrels. A chemical medium is then (or previously) applied to create the chemical or softening force adapted to place the wound tresses'in condition to be permanently molded and altered to their new form as determined by the winding. Finally, means are utilized to fix the wound tresses in their new form, which latter means may consist of an application of heat, generated electrically, chemically or in any other way followed by cooling or a second chemically reactive force to neutralize the chemical waving medium.

The present invention is concerned with the chemical medium which provides the chemical or softening force above referred to, this being identified hereinafter for descriptive purposes only as the waving solution, and comprising an aqueous solution containing the waving agent or agents.

Heretofore, the practice has been to use a waving agent for such solutions which is an alkaline material, for example, borax, various carbonates and phosphates of alkaline materials, ammonia and ammonium salts, such as the carbonates. Furthermore, soluble'sulfites of alkalies and ammonia have been utilized for the waving agent, and sulfides have also been provided for this purpose.

However, with respect to the sulfites and to all other heretofore utilized waving agents excepting'sulfides, relatively high concentrations are necessary in order to obtain any satisfactory permanent wave in the hair. Especially with fine hair, there is difi'iculty in providing a suitable waving solution for obtaining an altered form or shape for the hair which can be termed" permanent;

I have found that there is a limiting'concentration of these materials above which either hair destruction or injury occurs with less satisfactory wave. It is probably thisupward limiting effect on c'oncent'ration of these waving agents that make it impossible to obtain'satisfactory results in a short time where the hair is set by a-chemical force, for the solution containing these waving agents must be left in contact with the'hair for periods ranging from four to twenty-four hours before a satisfactory'wave may be obtained.

The sulfides do not require as long a timenor need quite as great a concentration as-the sulfites and'a satisfactory solution may "be made therefrom for" most types of hair and even fine hair under some conditions, but many disadvantages appear when usingsulfidesg the first of which is the 'characteristic'odor of rott'en' e'ggs possessed 2,736,323 Patented Feb. 28, 1956 by suchsulfides resulting from generation and liberation of free hydrogen sulfide by hydrolysis. All attempts to mask this odor result in failure and the use of heavy perfumes only serve to minimize the objectionable odor. Secondly, these sulfides havea tendency to cause tarnishing and blackening on metal, particularly jewelry, silverware, and the like, which is a further objection to their use in the waving lotion. Furthermore, the disgusting odor which accompanies the use ofsuch hydrogen sulfide salts is toxic to breathe and although normally the amount of hydrogen sulfide produced thereby is not dangerous, when in a confined booth or room such as a beauty shop cubicle often used in hair waving establishments, the concentration of the gas may become so high as to seriously aifect both operator and patron, unless expensive ventilating equipment is installed and maintained to remove this gas.

Thus, it will be seen that, while these sulfides are satisfactory in use in waving solutions from the point of view of performance or results in the finished permanent wave, they are wholly unsatisfactory because of the combined effect of toxicity, nauseating odor, and metallic coating effect.

More specifically, one of the best waving agents known for use when carrying out a permanent change of form or shape of the hair is ammonium hydrogen sulfide; but,

despite its relatively greater waving power, the use thereof is limited byliberation of hydrogen sulfide gas, together with'arnmonia gas. These evolved' gases make this compound very objectionable and perhaps dangerous, unless special precautions to remove the vapors, for instance, by suction ventilators, are taken.

Another objection to use of ammonium hydrogen sulfide and other sulfides is that the hair tends to retain the sulfide in spite of repeated rinsings even when using a chemical setting solution. The result is a mal-odor to the hair, particularly on each re-wetting. More important', however, is the fact that this retention by the hair of the sulfide atfords a continuous relaxing effect on the permanent wave with the result that the Wave become's'less tight with each re-wetting.

It isthe general objective of this invention to provide an agent for use in altering the permanent form or shape of hair which will be similar in its "elfect to that of the sulfides referred to above and yet will not possess the great disadvantages mentioned.

It isa further object of this invention to provide a lotion for the permanent waving of hair containing an entirely novel ingredient as the Waving agent which will give the solution a wide range of adaptability for permanent waving'of any type ortexture of hair.

It is a further object" of this invention to provide a non-odorous, non-toxic hair waving solution adapted to more rapidly and more successfully place hair in a condition to be altered in form or shape permanently, irrespective" of whether cooling subsequent" to heating or chemical meins is used after applying the waving solution in order to fix the hair in its new configuration.

It is a further object of this invention to provide a waving solution suitable for that type of permanent waving-of hair which utilizes a chemical action for the fixing of the hair in itswound form, such waving solution containing a waving agent as-powerful, rapid and satisfactory as ammonium hydrogen sulfide, but free from the limitations of ammonium hydrogen sulfide, particularly the bad odor and toxicity.

It is a further object of this invention to provide a waving solution powerful enough to wave hair without the need of added heat and which can be neutralized or completely removed by water alone; or, in other words, the wave can be fixed in the hair by washing out the waving agent-with water alone.

By this invention there is provided an agent for use in the permanent reforming of hair which is fast in action, satisfactory in use for all types of hair and yet is free from objectionable odors or toxicity or the like.-

I have discovered that I can obtain these objects by providing as a waving agent a mercaptan, or a mixture of mercaptans, whether the fixing of the new form for the hair be by cooling subsequent to heating, or by using chemical rinses or by any other method, and, further, that an elfective waving solution can be obtained by proper formulation including a mercaptan in water. The mercaptans are represented by the formula R--SH where R is an organic group such as the ethyl group in Ethyl mercaptan or the benzyl group in H CSH Benzyl mercaptan Such simple mercaptans will function adequately as Waving agents, but they still have the disadvantage of sulfides, such as ammonium hydrogen sulfide as far as bad odor is concerned.

I have discovered that bad odor, and other disadvantages can be entirely obviated by having the molecule contain other groups which are carefully selected, as hereinafter set forth, to give the optimum desired results. For instance, the mercaptan molecule may contain polar groups, which may be acidic groups. Examples of preferred compounds and groups of compounds belonging under the general heading of polar acidic substituted rnercaptans are: mercaptans containing the carboxylic groups, as for example, the simple mercapto-alkanoic acid, mercapto-acetic acid (thioglycollic). It is to be noted that any homologues could be used-also derivatives of these compounds such as salts, esters, amides, and the like.

I have discovered that all of the materials mentioned above function satisfactorily as hair waving agents when used in solutions. The concentration is usually less than 15%. I have found that the mercaptans are especially effective when the pH range is from 7.0 to 10.0, the preferred pH being about 9.2.

I have found that all alkaline materials are satisfactory for adjusting these pH, but that particularly effective with less hair destructive effect are bases having a dissociation constant less than 5X10 and preferably about In the cold waving process also I have found the volatile bases, such as ammonia, methylamine, and ethylamine are to be preferred with the mercaptans, since at the same pH value and mercaptan concentration solutions containing these volatile bases give tighter waves. Ammonia, therefore, is particularly to be preferred with the mercaptans since its ionization constant is satisfactory, its odor blends pleasantly with the mercaptans and it has a relatively non-irritating action in the desired pH range of 7.0 to 10.0.

This pH range is particularly critical when the waving agent is used for that type of waving employing a chemical setting agent, as in the so-called cold waving method, since in that system the necessary requirement of speed without hair destruction demands a high concentration of the waving agent in the waving solution. If the pH value is not high enough slow waving action will result and if too high the hair will be destroyed or badly damaged. While with sulfite a shorter waving time may require a pH of 10 or abovewith these more powerful waving agents, the use of pHs higher than 9.5 must be watched very carefully for with pH of 10 or above,

hair destruction or injury may occur before a satisfactory wave is obtained.

It is to be noted that organic sulfides and disulfides are not effective waving agents.

I have discovered that whereas all the mercaptans function very effectively in permanent waving where the final set is accomplished by heating and then cooling, when used in the so-called cold waving method requiring a chemical setting solution, unusual and startling differences from the prior art become apparent.

Furthermore, I have found that mercaptans containing polar groups are difficult to remove from the hair and whenever the hair becomes damp, for instance, in bathing, shampooing, or at sports such as skiing, the residual odor tends to offend. This is most observable with mercaptans containing polar alkaline groups such as B-amino ethyl mercaptan.

The odor effect is of tremendous importance, not only during the processing of the wave, but for a long time after the wave has been given. I have found that certain groups such as polar'groups tend to reduce the vapor pressure of the mercaptan and thus make the resulting mercaptan less objectionable.

I have also discovered that as the molecular weight increases, the rnercapto-alkanoic acids become less effective as waving agents, particularly if the increase is due to a polar acid group or to a polar alkaline group. For example, in the homologous series of simple mercapto-al kanoic acids, mercapto-acetic acid is more effective than mercapto-propionic acid which in turn is more effective than rnercapto-butyric acid; and the simple mercapto alkanoic acid, mercapto-hexanoic acid, is far more effective than the dicarboxylic acid, thiomalic acid, although these two mercaptans have almost identical molecular weights; and mercapto-butyric acid is far for eflicient as a waving agent than cysteine which has almost the same molecular weight but contains the polar alkaline'group, the amino group, in addition to the polar carboxyl group.

As illustrations of Waving solutions using the new waving agents according to this invention, the following specific example is given:

EXAMPLE Polar type-acidic Mercapto-acetic gms 10 Ammonium Hydroxide cc 10 Water q. s. sccss l00 I The waving solution in the above example may be utilized for effecting a cold wave by soaking the hair therein and applying thereafter a rinse. say, of sodium hypochlorite or other suitable rinse such as hydrogen peroxide, tartaric acid or the like. I have found that it is desirable to remove as'much of the solution of the waving agent as possible by first rinsing with water.

In the example given above the treatments resulted in satisfactory curls of medium tightness.

If the above example is used for waving where heat is employed, the concentration of the waving agent may be materially decreased, approximately to one third or one-fifth of the concentration given in the example.

Thus, the concentration of the Waving agent given in the above example, so decreased, would be:'

Mercapto acetic Q. gms. about 2 to 3.3

In considering this invention, it must also be borne in mind that a purpose is to provide a waving agent for use in a solution, the concentration of the waving agent beingmuch lower than heretofore effective commensurate with the desired effect of Waving the hair.

As a comparison of the "reduction of concentration of -the-waving ingredient provided by the instant invention as against that of one of the standard'waving agents used in this art, namely, sodium 'sulfite, I.have found that the same wave under the: same-. conditions of procedure can be given with abouttoneafifthofi the concentrationof my, new, waving agent. Thus, by'the. instant: invention; I can use. the same time of: operation but) greatlyreduce the concentrationof the .wavingingredient. Alternately, I can shorten the': time of waving by using a stronger. concentration but.still below the concentrations,

heretofore used; for instance. the sodium sulfite above mentioned, 1,. therefore provide a complete control of the wavingprocess bythe: waving, agent.

Utilizing the waving solution: of! anyof the examples, the. following, procedure, on onesimilar thereto, may be. employed ingiving a. permanent wave: The headv of hair/isv blocked. off. into sections andeach of the sectionedstrands is-rthenwell. soaked in the waving solution. mandrel to the: form. desired. and heat is then. applied, asv by a chemical. heating pad. arranged over the wound section. or by an electrical heating unit,,the temperature being raisedtoabout 212.F.,,tand-the hair, uponicooling, sets intoits. new configuration.

In giving; a cold. wave, procedures similar tothe following, which may be variouslyv modified, may be used:. The head of hair is again sectioned. off into strands. which are preferably wound on. mandrels, the

waving solution beingv applied before or. after winding bysoaking the'hair in. any. desired manner. After 'a-suitable lapse of. time for the. reaction, the hair is water rinsed,.andlthen achemicalrinse such as chlorine/watermay beapplied. which removes the. last trace of the waving. agent and thus assures. the fixing ofv the. hair in its: new configuration, whereafter the-hair will have a: permanent wave.

I have found thatinorderto reducethe'time of waving by, this chemicalmethod i. e., without..heat,.to a figure comparableto the time of waving-by heat it is .necessary to increase the concentration offlmercaptansin the waving solution. about three to. five times.

Thus,theconcentrations of mercaptans in the: above examples, when so increased from the concentrations suitable for Waving. with heat, ,would be as-follows-z Mercapto-acetic gms. about 6 to 10 Thus,-,it is possible to sof'select the concentrationaof my novel waving agent in the waving' solution.:that' the desiredtime of actualtreatmentbecomesfeasible, ranging from! a low: concentration with longer. time. of application as is desired in somemethods. of:cold waving,,or. a lowconcentration in continuous intimate contact with shorter time of application, or a low concentration with shorter timeusing heat, to higher concentrations .with decrease in time'whether the-fiization'is bychemical, orby cooling subsequent toheating; Since'thetim'e'of' waving is greaterwith lower concentrations andless with'hi'gh'er concentrations of mercaptans" and since, as described above,hthe I time of waving it greater with" a lower pH value and less with a higher pH" value,- it'foll'owsthat the concentratiorrof the mercaptan and the: pH of the solution; can. be adjusted.- Within' the ranges given. above to obtain a permanent change'in= theconfiguration of human-hair duringta given time-of application without damage to the.hair. structure byghaving the concentration of "mercaptan in the higher. portionof. the concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentration range for a higher pH'. But Ido not under any conditions use concentrations: higher: than heretofore used. Onthe contrary, comparing the time-concentratiomfa'ctorsofmy. novel waving agent with. waving: agents of thepriorjart for equivalent purposes,,it will.- be found that under all analogous conditions. I provide. a distinct reduction'in concentration wliile attaining optiinum-results inth'e' final waving.

While throughout" this specification I- have specifically mentioned:thewavingiof hair,,I do. not wish to limit Thereafter,-.each-.section:of hair is' woundlon the myself. thereto, since: by. this; invention it is. possible to permanently alteror reform the form, shape or configuration ofthe hair as desireda Thus,.my invention contemplates also the reverse of waving, such as de-kinking, removal. of curls. or waves, imparting of creases and the like; The waving solution according to this invention. may be-applied to the hair at any desired time,v either. before or after. winding or otherwise mechanically placing the hair. in. its reformed desired shape or. form. and by any desired. means, such as soaking, spraying,v continuous circulation or the. like, and the claimsareto be so-construedl Furthermore, while I have described examples offour invention andv have outlined advantages thereof over. the prior art, I do not wish to limit. myself to. the exact materials or proportions givenher'einbefore sinceayariety of like or similar materials may be used inlieu of. those specified and the pro portions thereof may be widely varied without departing from the spiritof. my invention or the intended scope of the appended claims.

What I.claim. is:-

1'. A permanent waving composition comprising a water. solutionof ammonia and about 2%. to 10% of thiogylcollic acid, said solution having a pH of about 9.2

1 the. concentration of said thioglycollic acid being adjusted. with respect to said pH.to obtain a permanent change in the configuration. of human hair during a given time of application at a temperature tolerable to the humanbody withoutdamage to the hair structure.

2. A permanent waving, composition comprising a water solution of ammonia and about'6% of thioglycollic acid, said solution having a pH of about 9.2.

3. A.. permanent waving'composition comprising a mercaptan selected'fr'oma group consisting of mercaptoacetic acid,. mercapto-propionic acid, mercapto-butyric acid, and mercapto-caproic acid, in a solution containing an alkaline materialhaving a dissociation constant less than.- 5 10 ,.said solutionhaving a pH ranging from about: 9.2 to. not. higher than 9.5, the concentration of said mercaptan. in terms 'of'weight per volume ranging from about- 2%- to. about 10%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to. obtain a. permanent change in the configuration'of human hair during a given time of application without damage to the hair structure by having. the concentration of mercaptan in the higher portion ofisaid. concentration range for a lower pH and having the concentration of mercaptan in the lower portion of. said concentration range for a higher pH within the statedrange.

4Q Afpermanenti waving composition in accordance with claim 9 in which themercaptan is mercapto acetic acid.-

5 A permanent waving composition in accordance with claim: 9- in which the mercaptan sis: mercapto-propionic acid.

6'.- A permanent :waving composition'iinaccordance with clai1'n9: in whichthemercaptan is mercapto-butyric acid.

7; A permanent waving co'mposition in'accordance with claim 9 in which the mercaptan" is mercapto-caproic acid.

8". A permanent'wavingcomposition comprising a mercaptan selctedfrom' the" group consisting of mercaptoacetic acid, mercapto-propi'onic acid, mercapto-butyric acid, and mereaptowapfroicacid, .in-a' solution containing an alkaline material having. a dissociation constant less than. 5x10 said" solution having a pH higher than pH 7 and nothig'h'er than pH9.5,.theconcentration of said mercaptan in: terms of weightpervolume ranging from. about. 2%, to about; 10%, the concentration of mercaptan and the pH-of the solution being adjusted within said ranges to obtain apermanent change inthe configurationsof human hairrduringa given# time of applicatiorrwithout damage-to the hairJst-ructure' by having the concentration:ofrmercaptan in the higher portion of said 7 concentration range for a lowerpH' andhaving the concentration of mercaptan in the-lower portion of said concentration range for a higher pH with'in the stated pH range.

9. A permanent waving composition comprising a mercaptan selected from the group consisting of mercaptoacetic acid, mercapto-propionic acid, mercapto-butyric acid, and mercapto-caproic acid, in a 'solution containing an alkaline material having a dissociation'constant less than 5X l said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of said mercaptan in terms of weight per volume ranging from about 2% to about 6%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application at temperatures tolerable to the human body without damage to the hair structure.

10. A permanent waving composition comprising a mercaptan selected from the group consisting of mercaptoacetic acid, mercapto-propionic acid; mercapto-butyric acid, and mercapto-caproic acid, in a solution containing an alkaline material having a dissociation constant less than 5X10- said solution having a pH ranging from about 9.2 to not higher than pH 9.5, the concentration of said mercaptan in terms of weight per volume ranging from about 2% to about 6%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application at temperatures tolerable to the human body without damage to the hair structure. I

11. A permanent waving composition comprising a mercaptan selected from the group consisting of mercaptoacetic acid, rnercapto-propionic acid, mercapto-butyric acid, and mercapto-caproic acid, in a solution containing an alkaline material having a dissociation constant less than 5 10 said solution having a pH of about 9.2, the concentration of said mercaptan in terms of weight per volume ranging from about 2% to about 10%, the concentration of mercaptan being adjusted with respect to said pH to obtain a permanent change in the configuration of human hair during a given time of application at temperatures tolerable to the human body without damage to the hair structure.

12. A permanent waving composition in accordance with claim 10 wherein the mercaptan is mercapto-acetic acid.

13. A permanent waving composition in accordance with claim 10 in which the mercaptan is mercapto-acetic acid; the pH of the solution is about 9.2; and the alkaline material is ammonium hydroxide.

14. A permanent waving composition in accordance with claim 11 in which the mercaptan is mercapto-acetic acid and the alkaline material is ammonium hydroxide.

15. The method of permanently changing the configuration of human hair without damage to the hair structure, including the steps of imparting the desired configuration to the hair and treating of the hair for a length of time with a permanent waving solution comprising a mercaptan selected from the group consisting of'mercaptoacetic acid, mercapto-propionic acid, mercapto-butyric acid, and mercapto-caproic acid, in a solution containing an alkaline material having a dissociation constant less than 5X 10*, said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of the mercaptan in terms of weight per volume ranging between about 2% and about 10%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure by having the con centration of mercaptan in the higher portion of said concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentrarange;

structure, including the steps of imparting the desired con-- figuration to the hair and treating of the hair for a length of time with a permanent waving solution comprising a mercaptan selected from the group consisting of mercaptoacetic acid, mercapto-propionic acid, mercapto-butyric acid, and mercapto-caproic acid, in a solution containing an alkaline material having a dissociation constant less than 5 l0 said solution having a pH ranging from about 9.2 to not higher than 9.5, the concentration of said mercaptan in terms of weight per volume ranging from about 2% to about 6%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application at a peratures tolerable to the human body without damage to the hair structure, and then fixing said configuration.

17. A method in accordance with claim 16 wherein the mercaptan is rnercapto-acetic acid and the alkaline material is ammonium hydroxide.

18. The method of permanently changing the configuration of hair on the living human scalp without damage to the hair structure, including the steps of imparting the desired configuration to the hair and treating of the hair with a permanent waving solution comprising ammonia and an amount of a thioglycolate equivalent to about 2% to about 10% of thioglycolic acid, said solution having a pH between 7 and 9.5, and then fixing said configuration.

19. A permanent waving composition comprising a water solution of ammonia and about 6% of thioglycolic acid, said solution having a pH of about 9.

20. A permanent waving composition in accordance with claim 3 wherein the alkaline material has a dissociation constant of about 10*".

21. A permanent waving composition in accordance with claim 3 wherein the mercaptan is mercapto-acetic acid.

22. The method of permanently changing the configuration of human hair without damage to the hair structure, including the steps of imparting the desired configuration to the hair and treating of the hair for a length of time with a permanent waving solution comprising a water solution of ammonia and about 2% to 10% of thioglycolic acid, said solution having a pH of about 9.2, and then fixing said configuration.

23. The method of permanently changing the configuration of human hair without damage to the hair structure, including the steps of imparting the desired configuration to thehair and treating of the hair for a length of time with a permanent waving solution comprising a water solution of ammonia and about 6% of thioglycolic acid, said solution having a pH of about 9.2, and then fixing said configuration.

24. A permanent waving composition in accordance with claim 8 wherein the alkaline material has a dissociation constant of about 10"? 25. A permanent waving composition in accordance with claim 9 wherein the alkaline material has a dissociation constant of about10- References Cited in the file of this patent UNITED STATES PATENTS 1,973,130 Turley Sept. 11, 1934 2,183,894 Pye Dec. 19, 1939 2,201,929 Speakman May 21, 1940 2,261,094 Speakman Oct. 28, 1941 2,352,524 Evans June 27, 1944 2,405,166 Reed et a1 Aug. 6,. 1946 (Other references on following page) 9 FOREIGN PATENTS 435,213 Great Britain Sept. 17, 1935 453,559 Great Britain Sept. 3, 1936 453,701 Great Britain Sept. 10, 1936 513,919 Great Britain Oct. 25, 1939 OTHER REFERENCES Turley and Windus: The Unhairing Problem, The Depilatory Action of Thio (-SH) Compounds, Stiasny- Festschrift, 1937, pages 396-406.

Bersin: Polarimetric Investigation of the Thiol-disulfide System, Chemical Abstracts (1938), pages 5283- 5284, abstract of Berichte, vol. 71 (1938), pages 1015- 1024.

Schoberl: Difi'erences in the Reactivity of Sulfhydril and Disulfide Groups in Organic Compounds, Chemical Abstracts (1939), page 964, abstract of Berichte, vol. 7113 (1938), pp. 2361-2371.

Mirsky et al.: Jour. Gen. PhysioL, volume 13, pages 307 to 323 (1934 to 1935) especially at page 312, for statement to effect that thioglycolic acid is an obvious equivalent for disrupting the disulfide linkages of proteins having disulfide linkages Leavell et al.: Determination of Iron, Analytical Ed, Ind. and Eng. Chem, vol. 6, No. 1, 1934, pages 46, 47.

Report of National Bureau of Standards (NBS Report) 10 File 5.8. Received in Patent Oflice February 5, 1951.

Schoberl: Die hydrolytische Aufspaltung tier Disulfidbindung, ein Beitrag zur Cheruie des Keratins, Collegium,

Piliemer et al.: Specificity of Keratins, Journal of Experimental Medicine, 1939, pages 191-197.

Goddard and Michaelis: A Study on Keratin, Journal of Biological Chemistry, vol. 106 (1934), pages 605-614.

McDonough: Mercaptans in Cosmetics, Journal of the Society of Cosmetic Chemists, July 1947, pp. 27-32.

Goddard and Michaelis: Derivatives of Keratin, Journal of Biological Chemistry, vol. 112 (1935-1936), pp. 361-371.

Michaelis: A Study of Keratin, Journal of American Leather Chemists Association, 1935, pages 561-568.

Speakman and Stoves: Reactivity of the Sulphur Linkage in Animal Fibres, J. Soc. Dyers and Colourists, June 1937, pp. 236-242.

Transcript of Record, United States Court of Customs and Patent Appeals, Patent Appeal Docket No. 5241, In the Matter of the Application of Samuel Grant, Appeal from Board of Appeals, Printed December 27, 1945, 57 pages plus 1 page Index.

Blackburn et al.: J. Soc. of Dyers & Colourists, September 1948, pages 305-314, page 305 esp. pertinent. 

9. A PERMANENT WAVING COMPOSITION COMPRISING A MERCAPTAN SELECTED FROM THE GROUP CONSISTING OF MERCAPTOACETIC ACID, MERCAPTO-PROPIONIC ACID, MERCAPTO-BUTYRIC ACID AND, MERCAPTO-CAPROIC ACID, IN A SOLUTION CONTAINING AN ALKALINE MATERIAL HAVING A DISSOCIATION CONSTANT LESS THAN 5X10-3, SAID SOLUTION HAVING A PH HIGHER THAN PH 7 AND NOT HIGHER THAN PH 9.5, THE CONCENTRATION OF SAID MERCAPTAN IN TERMS OF WEIGHT PER VOLUME RANGING FROM ABOUT 2% TO ABOUT 6%, THE CONCENTRATION OF MERCAPTAN AND THE PH OF THE SOLUTION BEING ADJUSTED WITHIN SAID RANGES TO OBTAIN A PERMANENT CHANGE IN THE CONFIGURATION OF HUMAN HAIR DURING A GIVEN TIME OF APPLICATION AT TEMPERATURES TOLERABLE TO THE HUMAN BODY WITHOUT DAMAGE TO THE HAIR STRUCTURE. 